Development of a Microcontroller Based Car Speed Controller

Abstract

Nigeria and many countries of the world have been experiencing an increase in road traffic accidents much of which can be attributed to human errors such as over speeding. The car speed controller discussed in this work is designed to automatically control the speed of a car so that the car’s speed will not exceed the speed limit that has been set for a particular zone by a regulating body such as the Federal Road Safety Commission (FRSC) in Nigeria. The car speed controller operates by taking inputs from a set of three switches that can set speed limits in kilometers per hour of 40, 80, and 120 respectively. Each setting of the switch is compared with the actual speed of the car that is derived from the car’s speedometer. If the speed of the car exceeds the setting, an actuator is called into operation such that the car’s speed is not allowed to exceed the set limit for the zone. A microcontroller was programmed to take inputs from the switches and the speedometer; depending on the settings the microcontroller turns on light emitting diodes (LEDs) and displays appropriate messages on the screen of a liquid crystal display (LCD). In the simulation model a stepper motor was controlled by the microcontroller through a motor driver to represent the adjustment of speed in the real environment. The program for the microcontroller was written using mikroC development environment and hardware simulation was carried out with the aid of Proteus Design Suite Version 8.0. The speed settings for a zone can be altered to suite the choice of a regulatory agency. The installation of the car speed controller in vehicles will not only give early warnings to drivers but will prevent over speeding thus leading to the reduction in cases of road traffic accidents.

Keywords: Car Speed Control, Speed Governor, Microcontroller, Road Safety